Emerald Ash Borer

Emerald Ash Borer

About the Emerald Ash Borer

The Emerald Ash Borer is an invasive beetle native to Asia that first landed in Ontario in 2002. Since then, the beetle has spread prolifically, destroying countless Ash trees. Here's a bit about the beetle, how to spot trees affected by them and what you can do to try and stop them. For more information visit the Ontario government site https://www.ontario.ca/page/emerald-ash-borer

The Emerald Ash Borer derives its name from the fact that it appears as an iridescent metallic green beetle (hence the name "emerald") and is a wood-boring insect that feeds almost exclusively on ash trees (Fraxinus). The beetle feeds on all ash species, including green, red, white, black and blue ash.

The female beetle lays 60-90 eggs in the bark of the ash tree. When the larvae hatch, they feed by chewing “S” shaped pathways under the bark. Unfortunately, this disrupts the tree's ability to send water and nutrients up its truck to the branches. This results in the leaves dying, which eventually destroys the branches and the whole tree.

Signs of an infection:

The pathways, or "galleries" left by the larvae, along with sawdust left behind by the boring insect, are a tell-tale sign of infection. And because the beetle starves the foliage, wilting or yellowing leaves is another indiction. You may also notice small "D" shaped holes in the bark, 4-5mm in size. These are exit holes made by adults leaving the infected tree.

What you can do about it:

If you have an ash tree that isn't infected yet, you can inject the tree with an approved insecticide. However, if your tree is already infected there is little to be done and early removal is recommended before the tree becomes hazardous.